Spherical plain bearings are known in the art. They are used, in particular, in ball-and-socket joints which are used in a very wide range of mechanical engineering sectors and particularly in the form of joint components of chassis and steering subassemblies in motor vehicle engineering. The plain bearing shell is installed in a bearing housing and surrounds a ball joint integrally formed on a joint pin. In principle, this geometry allows the joint pin to execute rotational movements in all spatial directions.
In a conventionally designed motor vehicle chassis, the supporting joints, for example, are in the form of grease-lubricated ball-and-socket joints. Aging of the lubricant and of the bearing partners regularly results in caking phenomena after a long stoppage, and so the ball joint “breaks away” from the bearing shell when the motor vehicle is reused. This can be accompanied by distinct cracking noises and can be a clear indication of advanced bearing wear.
GB 875,003 describes a self-lubricating spherical plain bearing of a ball-and-socket joint. The plain bearing shell of this spherical plain bearing is formed from two hemispherical shell elements made from a metallic material. The inner side of these shell elements, which faces toward the ball joint, is coated with a self-lubricating sliding material, for example a mixture of PTFE and lead. The outer edges of the hemispherical shell elements, which edges are situated opposite one another, are provided with bent flanges around which an outer clamping ring engages via its radially inwardly pointing flange. Rubber rings are arranged firstly between the flanges of the clamping ring and secondly between the outer flanges of the shell elements, and as a result the shell elements bear against the encompassed ball joint in a rubber-sprung manner.
The industry continues to demand improved spherical plain bearings with improved vibration damping.